I've been involved with the import tuning scene long enough to remember the days of when you'd buy a product and get installation directions on the back of a napkin. And sometimes the "kit" would be shipped without all the hardware you'd need to finish the installation.
Thankfully, the aftermarket seems to have caught on (or at least AEM has) and this AEM intake is truly a complete kit. Everything needed to perform the installation is included (well, except for the tools, of course). The system is engineered to fit in place using stock mounting points, making for a very clean install.
The instructions included are very thorough and the illustrations are quite helpful. I only found a few very minor points that could use a little more clarity, none of which are showstoppers. I have already provided a bit of feedback to AEM and I'm sure they will consider the suggestions to make the instructions even easier to use.
Now, for the results. To get consistent runs, at the minimum you need to stabilize the coolant and air intake temps for each dyno run. Using my OBD-II scanning tool, I ensured that this was the case for each of the runs on our 6MT TSX test car. First, we established the repeatable baseline runs. As you can see in the plot towards the end of the page, baseline power topped out at 177.5hp and torque came in at 157.9 lb-ft. These numbers are a little stronger than most stock TSX numbers I've seen (generally about 170whp, 152 lb-ft), so it's possible that the Hondata heat shield gasket contributed a few ponies. Oh, before I forget, at the time of the test, the subject vehicle was reading exactly 6400 miles on the odometer. Conditions were close to ideal, with an ambient temp of around 58 degrees F. The car's only oil change was performed at about 4000 miles.
While Arthur ran out to grab lunch, I got to work installing the intake. I figured it would take 45 minutes to an hour to remove the old intake and install the AEM SRS, but my guess was a little conservative. I actually finished the installation in around 35 minutes, and I was being deliberate and following the instructions to a "T". I should note that to eliminate any variables with respect to attaching the car to the dyno, we left it on the dyno while I did the installation.
With the intake installed, we fired up the car again, and after bringing the coolant temp back up to the same level as the earlier runs, we made a pass. The results were not too good. Scratching our heads, I noticed the check engine light was illuminated. Uh-oh. I looked on the OBD-II software screen and saw that an odd code had been thrown by the ECU. It was related to the IAT sensor. Thinking back, before installing the intake, I believe I accidentally disconnected the IAT sensor earlier while the ignition was still on (I was running the radiator fan to cool the car down quicker) and this likely tripped the code. Using my OBD-II tool, I reset the code and we made another pass (the same thing could be accomplished by pulling the fuse to the ECU and resetting it). This time the results were much better, beating the baseline by several hp. We made another pass and the car picked up a few more hp. The ECU was "learning" about the additional air the intake was providing. I decided to run the car "free" on the rollers for a few minutes to allow it to "learn" more about the additional air and make the proper fuel trim adjustments.
After this "learning period", we made another dyno pass and the car again made a bit more power. Subsequent runs were consistent with this pass so we decided that it had stabilized. The result? A peak of 185.7hp to the wheels, and 159.6 lb-ft of torque. According to our dyno runs, a bit of torque is lost below about 3000 rpms, but at 3300 rpms it starts making more torque (and thus power) than stock, and it continues delivering more power all the way to the 7300 rpm rev limiter. The peak gain is 8.2hp but peak torque is only up by about 1.7 lb-ft.
On the rollers the intake sounds similar to until about midway through the run. Then the note starts sounding a little more guttural than stock. As the revs build further, the sound starts growing in intensity and really lets loose when the big cams come online at 6000 rpms. You can hear for yourself in the following video clip which shows the TSX on the rollers with the stock intake and again with the AEM SRS.
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The sound on the road is much the same. Under part throttle and normal rpms, it could almost pass for stock. At full throttle and especially high rpms, it's quite a bit louder - almost menacing. Some TSX owners may find it a bit too overt for their tastes, but the additional power can be felt. Thanks to the K24's generous torque on the bottom end, you won't really notice much additional sound from the intake in even brisk day to day driving. It really only starts to get fairly loud as you exceed 5000rpms. At freeway speeds in the upper gears (4th-6th) you won't notice much of a difference until you get up to those higher rpms. The added sound adds a bit to the sensation of speed as well, something the stock TSX lacks (in stock configuration, it's sort of "sneaky" quick)
Even though the filter resides under the hood (it's not a "Cold Air Intake" per se), it doesn't seem to adversely impact the intake air temps. I monitored the IAT (Intake Air Temperature) sensor with my OBD-II scan tool while on the road and the readings were only about 15-20 degrees above ambient temperature. By comparison, the readings for the stock intake were virtually identical, also registering around 15-20 degrees above ambient temp. In both cases, the IAT climbs another 15-20F or so when the car stops moving, but as soon as you start moving again the IAT drops back to the 15-20F range.